An expert in working with refugees says recent arrivals to Australia from Syria and northern Iraq have the highest levels of trauma he has ever seen.

Paris Aristotle, who has worked with victims of wars and persecution from Vietnam, El Salvador, Bosnia and Sudan for 30 years, praised the Australian government's decision to accept 12,000 refugees from the region in the past two years.

The completion of the program was celebrated at a garden party hosted by Social Services Minister Christian Porter on Wednesday at Foundation House, the headquarters of Victorian Foundation for Survivors of Torture in Brunswick, which Mr Aristotle heads.

'She's going to be an Aussie': Week-old Melbourne-born baby Onita and her family from Iraq, father Faris Sora, mother Diana Shaheen and brothers Martin, 10, and Noorseen, 6, are grateful for their new life in Australia. Photo: Joe Armao

Mr Aristotle is chair of the settlement services advisory council for the program, which the federal government introduced outside its humanitarian refugee quota in response to IS' invasions of the Middle East.

While he didn't want to downplay the experiences of other communities, Mr Aristotle said "in my 30 years' experience in this field, the level of trauma amongst this group, and in particular amongst the children, is the highest I have seen".

"Many survived bombings of their villages, many of the kids witnessed people around them being executed and killed ...in several cases there are stories of children that were kidnapped and held hostage."

"The mass scale of it just seems to be more profound in terms of the breadth and impact on the community. And it's very recent. A lot of people that we've worked with for years spent time in camps for a long time...everyone here was born into, grew up in, or survived the conflict, and not that long ago."

Assyrian Christian Faris Sora, 36, of Broadmeadows, fled his home in Mosul, northern Iraq, with wife Diana Shaheen, 31, and sons Martin, now 10, and Noorseen, 6, as bombs fell during the IS invasion in 2014.

"We walked more than six hours north that night, with thousands of others. We saw people being killed and kids kidnapped."

They spent more than a year in Jordan, relying on the church for food, until they joined Mr Sora's uncle in Melbourne two years ago.

The boys are settled in school, although Martin remembers feeling scared and seeing rockets overhead in Iraq. Mr Sora is learning English and wants to train as a plumber.

The family is determined not to dwell on the past - particularly after Diana gave birth last week to a girl, Onita, meaning "dawn".

Mrs Sora said: "She's going to be an Aussie. She's going to have a good future here. She can study, she can do everything when she grows up."

Mr Sora said: "Everyone here helps us a lot. The people here respect each other. Whatever I say, it is not enough. I thank Australia for everything."